求助prep 一道语法（２．５考试，急）

huangruiyan

各位，帮我看看一道语法

Although the turtle has been toothless for more than 150 million years, in some contemporary turtle species the moderately sharp and jagged edges of their horny jaws function for teeth.

 

 

(A) their horny jaws function for teeth

(B) its horny jaws function for teeth

(C) its horny jaws function as do teeth

(D) the horny jaws function as teeth do

(E) the horny jaws function as teeth

整个句子的后半部分我就没有读懂，后面主句的谓语到底是谁呢，如果是function的话，为什么不选Ｂ呢，？

[此贴子已经被作者于2008-1-30 23:20:26编辑过]

小W

a,没有function for的用法

b,its应该为复数，因为turtle species；没有function for的用法

c,its应该为复数，因为turtle species；as do teeth，awkard，没必要倒装。

d,正确.句型为 A do as B do

e，as后面必须跟句子

后半句的意思大概是，"在同一时期一些乌龟种类具有相当锋利的边缘呈锯齿状的尖形下颚，起到了牙齿的作用"

希望不会误导你的考试。请指教。

brandie_who

我觉得E比较好看。。function as teeth，这里的as是介词，当作，作为的意思；而function就是后面半句的谓语

B的it不太象话，单数的代词没有指代，而且与后面复数的jaws也不搭。。

试着解释一下后半句：。。。在如今的乌龟种类里面，有点尖的，而且锯齿状的尖下巴（呵呵）就有牙齿的功能

小W

sorry.you are right. I made a mistake.

4. Although the turtle has been toothless for more than 150 million years, in some contemporary turtle species the moderately sharp and jagged edges of their horny jaws function for teeth.
A. their horny jaws function for teeth
B. its horny jaws function for teeth
C. its horny jaws functionas doteeth
D the horny jaws functionas teeth do
E the horny jaws function as teeth
A: function as n. 固定用法
B: its 指代错
C: 同上
D: function as n. 固定用法,这里不是as引导句子做比较
E: correct
注意:function as … 和 A do as B do 的逻辑意思区别

huangruiyan

谢谢大家。这道题的正确答案是Ｅ，。我刚才写错了，其实我不理解的是D，谢谢大家的解释，明了！